Adapted from Simply Recipes.
2 TBS butter
1 TBS olive oil
1 large onion, chopped
2 cups chopped cooked corned beef
1-2 cups chopped cooked beets*
1-2 cups chopped cooked potatoes*
1-2 cups cooked sweet potatoes*
1 tsp Worcestershire sauce
1 tsp dried parsley
Salt and pepper
*I recommend roasting the beets, sweet potatoes, and potatoes for this dish. It brings out their natural sweetness. Cut into 1/2" cubes and toss on a sheet pan with olive oil, salt, and pepper. Roast at 400 degrees for 20 minutes or until fork-tender and slightly browned.
Melt butter in olive oil on medium high heat. Saute onion until translucent. Add corned beef, beets, sweet potatoes and potatoes to the pan. Drizzle with Worcestershire sauce and sprinkle with salt, pepper, and parsley. Go easy on the salt if your potatoes are well-season as corned beef is salty.
Press mixture into even layer, reduce heat to medium and cook for a few minutes until a nice crust begins to form. (This step isn't really necessary for taste, just makes it prettier and adds a little more caramelization.)
Serve by itself or with eggs.